Relay matrix comprising polarized relays



M r 1967 H. v. ALEXANDERSSON 3,311,857

RELAY MATRIX COMPRISING POLARIZED RELAYS Filed April 21, 1965 r 2Sheets-Sheet 1 llllll llllll "'"NVENTOR. flmnzo /9LOFN9R Hz Exnwotnssowfirramvir's March 1967 H. v. ALEXANDERSSON 3,

RELAY MATRIX COMPRISING POLARIZED RELAYS Filed April 21, 1965 2Sheets-Sheet 2 (@IGJIQX r 1 VENTOR. Hmemo l/moume umomw United StatesPatent 3,311,857 I RELAY MATRIX COMPRISING POLARIZED I RELAYS HaraldValdemar Alexandersson, Lidingo, Sweden, assignor to TelefonaktiebolagetL M Ericsson, Stockholm, Sweden Filed Apr. 21, 1965, Ser. No. 449,740Claims priority, application Sweden, July 14, 1964, 8,567/ 64, 8,568/6413 Claims. ((Il. 335107) The present invention refers to a relay matrixprovided with a contact system of conductors crossing one another andwith polarized relays at the crossing points to actuate the contacts ofthese conductors.

A great difiiculty in the designing of electronic telephone systemsresides in the want of an electronic contact element that is suited forthe voice circuits of the system. Therefore, one has to useelectro-mechanical devices with metallic contacts. However, theconnection means used up to the present in automatic switching are notadequate forthe purpose in all respects.

Special relay structures, that are suited for electronically controlledselectors, have been proposed; examples thereof are the so calledferreed relays of different designs that usually comprise reed contactswith an external magnetic circuit including one or several remanentmagnetic elements, which relays can be combined in selectors of desiredcapacity. However, these structures ar usually clumsy and expensive.

An object of the invention is to eliminate these disadvantages and toachieve a relay matrix, that constitutes a simple and compact connectionmeans suited for electronic control. The invention is speciallycharacterized by a magnet system for polarization of the relays,comprising a plurality of parallel permanent magnets provided with polepieces. The pole pieces are in the form of parallel bars of magneticmaterial, that are located in two parallel planes through the ends ofthe permanent magnets. The permanent magnets are so oriented that ineach plane the pole pieces have alternately south pole and north polemagnetization. Each of the relays comprises a core of a material withtwo stable states of remanent magnetization and a winding. The cores areplaced in parallel relationship to the permanent magnets, whereby eachend of the cores is located in an opening between two bars in therespective plane. The relays are provided with movable elements in theform of balls disposed at the ends of the cores to contact the bars.

The contact system of the relay matrix comprises partly the bars and theballs and partly a number of metal contact strips placed perpendicularlyto the bars. Each one of the metal strips is arranged to cover the endsof a number of the relay cores in oneof the planes. The halls aremovably located on the contact strips.

The invention will be further described by means of an embodiment shownin the attached drawing in which FIG. 1 shows in schematic form a relaymatrix in plane view,

FIG. 2 shows the same device in a side view,

FIG. 3 shows another side view, wherein the cores of the permanentmagnets have been deleted to give a more clear view of the relay cores,and

FIG. 4 shows a single relay in a somewhat large scale. J

In the FIGURES 2-4 the windings of the relay cores have been indicatedbut in schematic form; the way the windings are located in the matrix isshown in FIGURES The matrix shown in FIGS. 1 to 3 comprises, forexample, 24 relay cores 1 of a bi-stable remanent magnetic material. Therelay cores are arranged in rows and 3,3 l 1,85? Patented Mar. 28, 1967columns, where each row contains four, each column six cores. Forpolarizing of the relays a number of permanent magnets 2 are providedeach one having a pair of elongated pole pieces 3 of magnetic material.

The permanent magnets with their poles pieces are so arranged, that thepole pieces are located in parallel relationship to each other along thecore rows, and that, on each side of the matrix, the pole pieces havealternately north pole and south pole magnetization. The distancebetween the pole pieces is substantially equal to the diameter of thecores, and the end surfaces of the cores are located in the center ofthe opening between the pole pieces (see FIG. 3 and FIG. 4).

Along each core column, contact metal strips 4 are placed below the polepieces 3 covering the end surfaces of the relay cores 1. On thesecontact strips a ball 5 of soft magnetic material is placed oppositeeach end surface of the relay cores. The contact system of the matrixcomprises partly the rigidly mounted pole pieces and the contact strips,which are insulated from the permanent magnets and from the relay coresas well as from each other, and partly the balls that, by the attractionforce of the cores are always in electric contact with the respectivecontact strips. According to the magnetization polarity of the relaycores, are pulled against one or the other of the two adjacent polespieces. All the pole pieces are on the one side provided with aninsulating layer 6 against which the balls are pulled in their inactiveposition.

The relay functions in the following manner (see FIG. '4). When thelower end of the relay core 1 has north pole magnetization and the upperend south pole magnetization, the magnetic field closes from the upperleft hand pole piece, that has north pole magnetization, through therelay core 1 to the lower left hand pole piece. The balls of the relayare attracted by the left 'hand pole pieces and rest against theinsulating layer 6 of the pole pieces. The field closes through theballs and the relay core, while the field from the right hand pole piecepair is repelled from the core. If the relay core is remagnetized by acurrent pulse through its Winding, so that the upper end of the core hasnorth pole magnetization and the lower end south pole magnetization, theballs 6 roll over to the position indicated by dotted lines, where theyclose a contact between the contact strips 4 and the right hand polepieces. The magnetic field consequently closes from the lower right handpole piece to the upper through the balls and the relay core, and thefield between the upper and lower left hand pole pieces is repelled fromthe relay core.

The windings of the relay matrix are so designed, that the individualrelays may be actuated through so called additive coincidence. Each corerow is provided with a winding that encircles the cores of the row andeach column is provided with a winding that encircles all the cores ofthe column as shown in FIG. 5. For magnetization of a certain relay coreit is necessary, that current simultaneously flows in the same directionthrough both windings that encircle the core in question i.e. throughthe winding of the row as well as through that of the column withinwhich the core is located. Other relays in the same row or column arenot magnetized, because they are only influenced by current through oneof their windings.

Because the pole pieces have alternately north pole and south polemagnetization (see FIG. 1), the magnetization direction for operating ofthe relays are different according to whether the cores are placed inrows With .even or odd numbers.

In windings for additive coincidence it is of importance, that both therow and the column windings are evenly distributed along the whole axiallength of the cores. This is achieved according to the invention bydividing the row windings as well the column windings in a plurality offractional windings each one with low number of turns, preferably asingle turn, and that the fractional windings corresponding to rows andalso columns are alternately located along the axial direction of thecore. Thus, in FIG. 7 there is shown the outer core row with its rowwinding 7 and its column windings 8. Such a winding may easily bemanufactured by means of a machine, that mounts alternately fractionalrow windings and fractional column windings. If so desired, the wholewinding may be impregnated eventually together with the cores in athermosetting resin.

I claim:

1. A relay switching device comprising a core of bistably remanentmaterial, said core having at least a first end, a conductor member ofelectrically conductive material disposed near said first end of saidcore, a permanent magnet means including at least first and secondoppositely polarized pole pieces straddling said first end of said coreand adjacent said conductor member, a rollable member of electricallyconductive ferromagnetic material disposed on said conductor member androllable to selectively contact one of said pole pieces, and a windinginductively coupled to said core and adapted to receive a switchingcurrent for controllably establishing the polarity of the remanentmagnetization in the core and thereby control the contacting of saidrollable member with a selected one of said pole pieces so that anelectrical path is established from said conductor member via saidrollable member to the selected pole piece.

2. A relay switching device comprising a core of bistably remanentmagnetic material, said core having first and second ends, a conductormember of electrically conductive material disposed near one end of saidcore, a first permanent magnet means including first and second polepieces adjacent, respectively, the first and second ends of said core, asecond permanent magnet means including first and second pole piecesadjacent respectively the first and second ends of said core, the first.pole pieces of each of said permanent magnet means being spaced fromeach other and adjacent said conductor member, said permanent magnetmeans being so polarized that their first pole pieces are oppositelypolarized and their second pole pieces are oppositely polarized, arollable member of conductive material disposed on said conductor memberand rollable to contact at any given time one of said first pole pieces,and a winding disposed about said core and adapted to receive aswitching current for controllably establishing the polarity of theremanent magnetization in the core and thereby control the contacting ofsaid rollable member to a selected one of said first pole pieces.

3. The device of claim 2 wherein said rollable member is a ball. a

4. A relay switching device comprising a core of bistably remanentmagnetic material, said core having first and second ends, first andsecond conductor members of electrically conductive material disposednear the first and second ends, respectively, of said core, first andsecond permanent magnet means, each of said permanent magnet meanscomprising a permanent magnet and first and second pole pieces, saidfirst pole pieces being disposed adjacent to the first end of said corein mutually spaced relationship, said second pole pieces being disposedadjacent to the second end of said core and in mutually spacedrelationship, said permanent magnets being magnetized with respect toeach other so that the first pole piece of said first permanent magnetmeans and the second pole piece of said second permanent magnet meanshave the same polarization, said same polarization being opposite to thepolarization of the first pole piece of said second permanent magnetmeans and the second gpole piece of said first permanent magnet means, afirst rollable conductor of ferromagnetic material disposed on saidfirst conductor member and being rollable to selectively contact one ofsaid first pole pieces at a time, a second rollable conductor offerromagnetic material disposed on said second conductor member andbeing rollable to selectively contact one of said second pole pieces ata time, and a win-ding inductively coupled to said core and adapted toreceive a switching current for controllably establishing the polarityof the remanent magnetization in the core and thereby control thecontact of said rollable members to a selected one of said first polepieces and a corresponding one of said second pole pieces.

5. The device of claim 4 wherein said controllable members are balls.

6. A relay switching matrix comprising a plurality of cores of bi-stablyremanent magantic material, said cores being arrayed in rows andcolumns, each of said cores having first and second ends aligned inplanes, a plurality of first conductive elements, each of said firstconductive elements being disposed opposite the first ends of the coresin one of the rows, respectively, a plurality of permanent magnet means,each of said permanent magnet means including at least a first linearand electrically conductive pole piece extending in a plane parallel tothe plane of the first ends of said cores, said first pole piecesextending along lines orthogonal to said first conductive elements anddisposed laterally to a column or cores whereby the first end of eachcore in the rows of cores is straddled by portions of two adjacent firstpole pieces and the portion of the associated first conductive elementopposite the first end of the core is similarly straddled, saidpermanent magnet means being so polarized that said first pole piecessequentially alternate in polarity, a plurality of first rollableelectrically conductive elements of ferromagnetic material, each of saidfirst rollable elements being disposed on a portion of a firstconductive element directly opposite the first end of a core androllable to selectively contact the portion of either of the first polepieces stradd'ling said portion of said first conductive element,winding means associated with each of said cores for changing itsremanent magnetic state to cause the associated first rollable elementto simultaneously contact a preselected first pole piece and theassociated first conductive element.

7. The relay switching matrix of claim 6 wherein each of said polepieces has first and second sides contactable by said rollable membersand further comprising means for electrically insulating the first sideof each of said pole pieces. 7

8. The relay switching matrix of claim 6 wherein said winding meansincludes a plurality of first windings, each of said first windingsbeing inductively coupled to each core in one of said rows,respectively, and a plurality of second windings, each of said secondwindings being inductively coupled to each core in one of said columns,respectively.

9. The relay switching matrix of claim 8 wherein each of the secondwindings inductively couples alternate cores of its associated column ofcores in magnetically opposite directions.

10. The relay switching matrix of claim 6 wherein said first rollableelement are balls.

11. The relay switching matrix of claim 6 further comprising a pluralityof second conductive elements, each of said second conductive elementsbeing disposed opposite the second ends of the cores of one of the rows,respectively; wherein each of said permanent magnet means furtherincludes a second linear and electrically conductive pole pieceextending in a plane parallel to the plane of the second ends of saidcores, each of said second pole pieces extending along a line parallelto one of said first pole pieces, respectively, whereby the second endof each core in the rows of cores is straddled by portions of twoadjacent second pole pieces and the portion of the associated secondconductive element opposite the second end of the core is similarlystraddled; and further comprosing a plurality of second rollableelectrically conductive elements of ferromagnetic material, each of saidsecond rollable elements being disposed on a portion of a secondconductive element directly opposite the second end of a core androllable to selectively contact the portion of either of the sec-0ndpole pieces straddling said portion of said conductive element, saidsecond rollable magnetic elements being similarly influenced by theremanent magnetization of said cores to simultaneously contact apre-selected second pole piece and the associated second conductiveelement.

12. A relay matrix comprising a plurality of relay means, each of saidrelay means including a relay core, said relay cores being arrayed inrows and columns, a plurality of row Winding means, each of said rowwinding means being inductively coupled to each of the cores in a row,respectively, and a plurality of column winding means, each of saidcolumn winding means being inductively coupled to each of the cores incolumn respectively, each of said row winding means comprising aplurality of row windings, each of said row windings including at leasta portion 'of the row turn disposed about each core of the row,respectively, and each of said column winding means comprising aplurality of column windings, each of said column windings including atleast a portion of a column turn disposed about each of the cores of thecolumn, re-

spectively, with respect to each core the row and column turnsassociated therewith being interleaved along the axial direction of thecore.

13. A relay switching device comprising a first core, said first corehaving at least a first end, a conductor member of electricallyconductive material disposed near said first end of said first core, asecond core, said second core including first and a second pole piecesstraddling said first end of said first core and adjacent said conductormember, one of said cores being of a by-stably remanent magneticmaterial and including a winding for changing the state of remanentmagnetization of said core, the other of said cores being a permanentmagnet, and a rollable member of electrically conductive ferromagneticmaterial disposed on said conductor member and rollable tosimultaneously contact said conductor member and one of said polepieces, said one of said pole pieces being determined by the state ofremanent magnetization of said one of said.

cores.

References Cited by the Examiner UNITED STATES PATENTS 3,175,062 3/1965Bobeck 20087 BERNARD A. GILHEANY, Primary Examiner. R. N. EVALL,Assistant Examiner.

1. A RELAY SWITCHING DEVICE COMPRISING A CORE BISTABLY REMANENT MATERIAL, SAID CORE HAVING AT LEAST A FIRST END, A CONDUCTOR MEMBER OF ELECTRICALLY CONDUCTIVE MATERIAL DISPOSED NEAR SAID FIRST END OF SAID CORE, A PERMANENT MAGNET MEANS INCLUDING AT LEAST FIRST AND SECOND OPPOSITELY POLARIZED POLE PIECES STRADDLING SAID FIRST END OF SAID CORE AND ADJACENT SAID CONDUCTOR MEMBER, A ROLLABLE MEMBER OF ELECTRICALLY CONDUCTIVE FERROMAGNETIC MATERIAL DISPOSED ON SAID CONDUCTOR MEMBER AND ROLLABLE TO SELECTIVELY CONTACT ONE OF SAID POLE PIECES, AND A WINDING INDUCTIVELY COUPLED TO SAID CORE AND ADAPTED TO RECEIVE A SWITCHING CURRENT FOR CONTROLLABLY ESTABLISHING THE POLARITY OF THE REMANENT MAGNETIZATION IN THE CORE AND THEREBY CONTROL THE CONTACTING OF SAID ROLLABLE MEMBER WITH A SELECTED ONE OF SAID POLE PIECES SO THAT AN ELECTRICAL PATH IS ESTABLISHED FROM SAID CONDUCTOR MEMBER VIA SAID ROLLABLE MEMBER TO THE SELECTED POLE PIECE. 